Electric safety lock



H. BIEN ERT ELECTRIC SAFETY LOCK Flled Feb 6, 1926 Jan.

?atenteel Jan. 11, 192?.

PATENT OFFICE.

HEIjMANN BIENERT, OF :BEUTHEN, GERMANY.

nrno'rnro SAFETY 1001:.

Application filed February This invention relates to a lock comprising a locking of the locking hook adapted to be electrically released, in which the alternating current circuit for exciting the electro-magnet may be switched in from outside or inside the house or flat, from the inside by a press-button (or switch) from the outside by means of a contact known only to the initiated and to be adjusted by a threaded key.

The electric safety lock is independent of any ordinary lock and can be mounted on any kind of door provided an electric light plant exists.

In the accompanying drawings Fig. 1 shows the electric safety lock partly in front elevation and partly in section on line 1-1 of Fig. 2.

Fig. 2 is a section on line 22 of Fig. 1.

Fig. 3 is a section on line 33 of Fig. 1.

Fig. 4 is a section on line 44 of Fig. 1.

The leading in wires 1 and 1 from the electric lighting plant which enter into the upper part of the safety lock terminate at he contact springs (6 b of a push button a aid contact springs being each connected with one pole of the electro-magnet 70. Under the electro-magnet is an armature lever (Z is pivotally mounted which co-opcrates with alocking hook e fixed on the door post.

If from inside the door the button 0 pushed the circuit of the electro-inagnet 7c is closed and the lever (Z is attracted by the electro-magnet whereby the lock is unlocked so that by means of the latch key or the door handle the door can be opened.

To open the safety look from the outer side of the door a key has to be inserted into a hole bored through the door at the height of the push button 0 said hole having a inner diameter of about 4 mm. corresponding to the outer diameter of the key 2'. In the key a nut is fixed which is to be screwed upon a threaded stud fixed on the contact spring a so that this contact spring is pulled against the contact spring I) closing the circuit through the electromagnet k so that the lever (Z is attracted and the looking hook 0 released.

It is diflicult to imitate the key as in an impression of Wax the threads will be destroyed when the Wax impression is taken 6, 1926. Serial No. 86,674.

out. The lock issues when opened a rather loud buzzing noise which frightens the house breaker, and the lock may further be connected with an alarm signal.

In case of short-circuit or failing of current it would not be possible to open the lock from the outer side of the door. For this reason a spring device f is arranged. The spring 7 is compressed by a safety pin 9. This pin 5/ has a diameter of 1 to 2 mm. and is located in a narrow hole bored through the door. If a pin is inserted into the narrow hole 79 covered at the outer end by wax of the same colour as the door is tinted (Fig. 4) the pin 9 is pushed out so that the spring f is no longer retained and pushes the lever (Z up so that the locking hook e is released. If the electric line is in order again the safety pin 9 is reinserted into the hole 9.

To render the safety lock inoperative a short arm it is pivotally mounted underneath the lever (Z, said arm being normally in the position shown in Fig. 1 in full lines. If this arm is rotated 90 into the position shown in dotted lines in Fig. 1, the arm. 7t lifts the lever (Z and maintains it in this lifted position. To render the safety lock operative the arm h is returned into the initial position.

I claim An. electric safety lock comprising in combination a locking hook fixed on the door post, a lock plate fixed on the door, an electromagnet on said door plate, a lever pivotally mounted under said electromagnet so that it isnormally in looking engagement with said locking hook, two contact springs on said plate above said electromagnet said contact springs being inserted in an electric circuit fed from the electric light plant, a push button on the inner one of'said contact springs. and a threaded pin on the other side of said inner contact spring, said pin projecting into a hole bored into the door so that a key with a nut fitting on said threaded pin can be inserted through said hole for pulling the said contact spring against the other contact spring to close the circuit so that the safety lock can be opened from the outer side of the door.

In testimony whereof I aflix my signature.

HERMAN'N BIENERT.

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